1 /*
  2  * Copyright (c) 1999, 2022, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.  Oracle designates this
  8  * particular file as subject to the "Classpath" exception as provided
  9  * by Oracle in the LICENSE file that accompanied this code.
 10  *
 11  * This code is distributed in the hope that it will be useful, but WITHOUT
 12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 14  * version 2 for more details (a copy is included in the LICENSE file that
 15  * accompanied this code).
 16  *
 17  * You should have received a copy of the GNU General Public License version
 18  * 2 along with this work; if not, write to the Free Software Foundation,
 19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 20  *
 21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 22  * or visit www.oracle.com if you need additional information or have any
 23  * questions.
 24  */
 25 
 26 package com.sun.tools.javac.code;
 27 
 28 import java.util.Collection;
 29 import java.util.Collections;
 30 import java.util.EnumSet;
 31 import java.util.HashMap;
 32 import java.util.LinkedHashMap;
 33 import java.util.Map;
 34 
 35 import javax.lang.model.element.ElementVisitor;
 36 
 37 import com.sun.tools.javac.code.Scope.WriteableScope;
 38 import com.sun.tools.javac.code.Source.Feature;
 39 import com.sun.tools.javac.code.Symbol.ClassSymbol;
 40 import com.sun.tools.javac.code.Symbol.Completer;
 41 import com.sun.tools.javac.code.Symbol.CompletionFailure;
 42 import com.sun.tools.javac.code.Symbol.MethodSymbol;
 43 import com.sun.tools.javac.code.Symbol.ModuleSymbol;
 44 import com.sun.tools.javac.code.Symbol.PackageSymbol;
 45 import com.sun.tools.javac.code.Symbol.RootPackageSymbol;
 46 import com.sun.tools.javac.code.Symbol.TypeSymbol;
 47 import com.sun.tools.javac.code.Symbol.VarSymbol;
 48 import com.sun.tools.javac.code.Type.BottomType;
 49 import com.sun.tools.javac.code.Type.ClassType;
 50 import com.sun.tools.javac.code.Type.ErrorType;
 51 import com.sun.tools.javac.code.Type.JCPrimitiveType;
 52 import com.sun.tools.javac.code.Type.JCVoidType;
 53 import com.sun.tools.javac.code.Type.MethodType;
 54 import com.sun.tools.javac.code.Type.UnknownType;
 55 import com.sun.tools.javac.code.Type.WildcardType;
 56 import com.sun.tools.javac.code.Types.UniqueType;
 57 import com.sun.tools.javac.comp.Modules;
 58 import com.sun.tools.javac.jvm.Target;
 59 import com.sun.tools.javac.util.Assert;
 60 import com.sun.tools.javac.util.Context;
 61 import com.sun.tools.javac.util.Convert;
 62 import com.sun.tools.javac.util.DefinedBy;
 63 import com.sun.tools.javac.util.DefinedBy.Api;
 64 import com.sun.tools.javac.util.Iterators;
 65 import com.sun.tools.javac.util.JavacMessages;
 66 import com.sun.tools.javac.util.List;
 67 import com.sun.tools.javac.util.Name;
 68 import com.sun.tools.javac.util.Names;
 69 import com.sun.tools.javac.util.Options;
 70 
 71 import static com.sun.tools.javac.code.Flags.*;
 72 import static com.sun.tools.javac.code.Kinds.Kind.*;
 73 import static com.sun.tools.javac.code.TypeTag.*;
 74 
 75 /** A class that defines all predefined constants and operators
 76  *  as well as special classes such as java.lang.Object, which need
 77  *  to be known to the compiler. All symbols are held in instance
 78  *  fields. This makes it possible to work in multiple concurrent
 79  *  projects, which might use different class files for library classes.
 80  *
 81  *  <p><b>This is NOT part of any supported API.
 82  *  If you write code that depends on this, you do so at your own risk.
 83  *  This code and its internal interfaces are subject to change or
 84  *  deletion without notice.</b>
 85  */
 86 public class Symtab {
 87     /** The context key for the symbol table. */
 88     protected static final Context.Key<Symtab> symtabKey = new Context.Key<>();
 89 
 90     /** Get the symbol table instance. */
 91     public static Symtab instance(Context context) {
 92         Symtab instance = context.get(symtabKey);
 93         if (instance == null)
 94             instance = new Symtab(context);
 95         return instance;
 96     }
 97 
 98     private final boolean allowPrimitiveClasses;
 99 
100     /** Builtin types.
101      */
102     public final JCPrimitiveType byteType = new JCPrimitiveType(BYTE, null);
103     public final JCPrimitiveType charType = new JCPrimitiveType(CHAR, null);
104     public final JCPrimitiveType shortType = new JCPrimitiveType(SHORT, null);
105     public final JCPrimitiveType intType = new JCPrimitiveType(INT, null);
106     public final JCPrimitiveType longType = new JCPrimitiveType(LONG, null);
107     public final JCPrimitiveType floatType = new JCPrimitiveType(FLOAT, null);
108     public final JCPrimitiveType doubleType = new JCPrimitiveType(DOUBLE, null);
109     public final JCPrimitiveType booleanType = new JCPrimitiveType(BOOLEAN, null);
110     public final Type botType = new BottomType();
111     public final JCVoidType voidType = new JCVoidType();
112 
113     private final Names names;
114     private final JavacMessages messages;
115     private final Completer initialCompleter;
116     private final Completer moduleCompleter;
117 
118     /** A symbol for the unnamed module.
119      */
120     public final ModuleSymbol unnamedModule;
121 
122     /** The error module.
123      */
124     public final ModuleSymbol errModule;
125 
126     /** A symbol for no module, for use with -source 8 or less
127      */
128     public final ModuleSymbol noModule;
129 
130     /** A symbol for the root package.
131      */
132     public final PackageSymbol rootPackage;
133 
134     /** A symbol that stands for a missing symbol.
135      */
136     public final TypeSymbol noSymbol;
137 
138     /** The error symbol.
139      */
140     public final ClassSymbol errSymbol;
141 
142     /** The unknown symbol.
143      */
144     public final ClassSymbol unknownSymbol;
145 
146     /** A value for the errType, with a originalType of noType */
147     public final Type errType;
148 
149     /** A value for the unknown type. */
150     public final Type unknownType;
151 
152     /** The builtin type of all arrays. */
153     public final ClassSymbol arrayClass;
154     public final MethodSymbol arrayCloneMethod;
155 
156     /** VGJ: The (singleton) type of all bound types. */
157     public final ClassSymbol boundClass;
158 
159     /** The builtin type of all methods. */
160     public final ClassSymbol methodClass;
161 
162     /** A symbol for the java.base module.
163      */
164     public final ModuleSymbol java_base;
165 
166     /** Predefined types.
167      */
168     public final Type objectType;
169     public final Type objectMethodsType;
170     public final Type objectsType;
171     public final Type classType;
172     public final Type classLoaderType;
173     public final Type stringType;
174     public final Type stringBufferType;
175     public final Type stringBuilderType;
176     public final Type cloneableType;
177     public final Type serializableType;
178     public final Type serializedLambdaType;
179     public final Type varHandleType;
180     public final Type methodHandleType;
181     public final Type methodHandlesType;
182     public final Type methodHandleLookupType;
183     public final Type methodTypeType;
184     public final Type nativeHeaderType;
185     public final Type throwableType;
186     public final Type errorType;
187     public final Type interruptedExceptionType;
188     public final Type illegalArgumentExceptionType;
189     public final Type exceptionType;
190     public final Type runtimeExceptionType;
191     public final Type classNotFoundExceptionType;
192     public final Type noClassDefFoundErrorType;
193     public final Type noSuchFieldErrorType;
194     public final Type assertionErrorType;
195     public final Type incompatibleClassChangeErrorType;
196     public final Type cloneNotSupportedExceptionType;
197     public final Type matchExceptionType;
198     public final Type annotationType;
199     public final TypeSymbol enumSym;
200     public final Type listType;
201     public final Type collectionsType;
202     public final Type comparableType;
203     public final Type comparatorType;
204     public final Type arraysType;
205     public final Type iterableType;
206     public final Type iteratorType;
207     public final Type annotationTargetType;
208     public final Type overrideType;
209     public final Type retentionType;
210     public final Type deprecatedType;
211     public final Type suppressWarningsType;
212     public final Type supplierType;
213     public final Type inheritedType;
214     public final Type profileType;
215     public final Type proprietaryType;
216     public final Type systemType;
217     public final Type autoCloseableType;
218     public final Type trustMeType;
219     public final Type lambdaMetafactory;
220     public final Type stringConcatFactory;
221     public final Type repeatableType;
222     public final Type documentedType;
223     public final Type elementTypeType;
224     public final Type functionalInterfaceType;
225     public final Type previewFeatureType;
226     public final Type previewFeatureInternalType;
227     public final Type typeDescriptorType;
228     public final Type recordType;
229     public final Type switchBootstrapsType;
230     public final Type constantBootstrapsType;
231     public final Type valueBasedType;
232     public final Type valueBasedInternalType;
233     public final Type classDescType;
234     public final Type enumDescType;
235 
236     // For serialization lint checking
237     public final Type objectStreamFieldType;
238     public final Type objectInputStreamType;
239     public final Type objectOutputStreamType;
240     public final Type ioExceptionType;
241     public final Type objectStreamExceptionType;
242     // For externalization lint checking
243     public final Type externalizableType;
244     public final Type objectInputType;
245     public final Type objectOutputType;
246 
247     // For string templates
248     public final Type stringTemplateType;
249     public final Type templateRuntimeType;
250     public final Type processorType;
251     public final Type linkageType;
252 
253     /** The symbol representing the length field of an array.
254      */
255     public final VarSymbol lengthVar;
256 
257     /** The symbol representing the final finalize method on enums */
258     public final MethodSymbol enumFinalFinalize;
259 
260     /** The symbol representing the close method on TWR AutoCloseable type */
261     public final MethodSymbol autoCloseableClose;
262 
263     /** The predefined type that belongs to a tag.
264      */
265     public final Type[] typeOfTag = new Type[TypeTag.getTypeTagCount()];
266 
267     /** The name of the class that belongs to a basic type tag.
268      */
269     public final Name[] boxedName = new Name[TypeTag.getTypeTagCount()];
270 
271     /** A hashtable containing the encountered top-level and member classes,
272      *  indexed by flat names. The table does not contain local classes.
273      *  It should be updated from the outside to reflect classes defined
274      *  by compiled source files.
275      */
276     private final Map<Name, Map<ModuleSymbol,ClassSymbol>> classes = new HashMap<>();
277 
278     /** A hashtable containing the encountered packages.
279      *  the table should be updated from outside to reflect packages defined
280      *  by compiled source files.
281      */
282     private final Map<Name, Map<ModuleSymbol,PackageSymbol>> packages = new HashMap<>();
283 
284     /** A hashtable giving the encountered modules.
285      */
286     private final Map<Name, ModuleSymbol> modules = new LinkedHashMap<>();
287 
288     private final Map<Types.UniqueType, VarSymbol> classFields = new HashMap<>();
289 
290     public VarSymbol getClassField(Type type, Types types) {
291         return classFields.computeIfAbsent(
292             new UniqueType(type, types), k -> {
293                 Type arg = null;
294                 if (type.getTag() == ARRAY || type.getTag() == CLASS) {
295                     /* Temporary treatment for primitive class: Given a primitive class V that implements
296                        I1, I2, ... In, V.class is typed to be Class<? extends Object & I1 & I2 .. & In>
297                     */
298                     if (allowPrimitiveClasses && type.isPrimitiveClass()) {
299                         List<Type> bounds = List.of(objectType).appendList(((ClassSymbol) type.tsym).getInterfaces());
300                         arg = new WildcardType(bounds.size() > 1 ? types.makeIntersectionType(bounds) : objectType, BoundKind.EXTENDS, boundClass);
301                     } else {
302                         arg = types.erasure(type);
303                     }
304                 }
305                 else if (type.isPrimitiveOrVoid())
306                     arg = types.boxedClass(type).type;
307                 else
308                     throw new AssertionError(type);
309 
310                 Type t = new ClassType(
311                     classType.getEnclosingType(), List.of(arg), classType.tsym);
312                 return new VarSymbol(
313                     STATIC | PUBLIC | FINAL, names._class, t, type.tsym);
314             });
315     }
316 
317     public void initType(Type type, ClassSymbol c) {
318         type.tsym = c;
319         typeOfTag[type.getTag().ordinal()] = type;
320     }
321 
322     public void initType(Type type, String name) {
323         initType(
324             type,
325             new ClassSymbol(
326                 PUBLIC, names.fromString(name), type, rootPackage));
327     }
328 
329     public void initType(Type type, String name, String bname) {
330         initType(type, name);
331         boxedName[type.getTag().ordinal()] = names.fromString("java.lang." + bname);
332     }
333 
334     /** The class symbol that owns all predefined symbols.
335      */
336     public final ClassSymbol predefClass;
337 
338     /** Enter a class into symbol table.
339      *  @param s The name of the class.
340      */
341     private Type enterClass(String s) {
342         return enterClass(java_base, names.fromString(s)).type;
343     }
344 
345     public void synthesizeEmptyInterfaceIfMissing(final Type type) {
346         final Completer completer = type.tsym.completer;
347         type.tsym.completer = new Completer() {
348             @Override
349             public void complete(Symbol sym) throws CompletionFailure {
350                 try {
351                     completer.complete(sym);
352                 } catch (CompletionFailure e) {
353                     sym.flags_field |= (PUBLIC | INTERFACE);
354                     ((ClassType) sym.type).supertype_field = objectType;
355                 }
356             }
357 
358             @Override
359             public boolean isTerminal() {
360                 return completer.isTerminal();
361             }
362         };
363     }
364 
365     public void synthesizeBoxTypeIfMissing(final Type type) {
366         ClassSymbol sym = enterClass(java_base, boxedName[type.getTag().ordinal()]);
367         final Completer completer = sym.completer;
368         sym.completer = new Completer() {
369             @Override
370             public void complete(Symbol sym) throws CompletionFailure {
371                 try {
372                     completer.complete(sym);
373                 } catch (CompletionFailure e) {
374                     sym.flags_field |= PUBLIC;
375                     ((ClassType) sym.type).supertype_field = objectType;
376                     MethodSymbol boxMethod =
377                         new MethodSymbol(PUBLIC | STATIC, names.valueOf,
378                                          new MethodType(List.of(type), sym.type,
379                                 List.nil(), methodClass),
380                             sym);
381                     sym.members().enter(boxMethod);
382                     MethodSymbol unboxMethod =
383                         new MethodSymbol(PUBLIC,
384                             type.tsym.name.append(names.Value), // x.intValue()
385                             new MethodType(List.nil(), type,
386                                 List.nil(), methodClass),
387                             sym);
388                     sym.members().enter(unboxMethod);
389                 }
390             }
391 
392             @Override
393             public boolean isTerminal() {
394                 return completer.isTerminal();
395             }
396         };
397     }
398 
399     // Enter a synthetic class that is used to mark classes in ct.sym.
400     // This class does not have a class file.
401     private Type enterSyntheticAnnotation(String name) {
402         // for now, leave the module null, to prevent problems from synthesizing the
403         // existence of a class in any specific module, including noModule
404         ClassType type = (ClassType)enterClass(java_base, names.fromString(name)).type;
405         ClassSymbol sym = (ClassSymbol)type.tsym;
406         sym.completer = Completer.NULL_COMPLETER;
407         sym.flags_field = PUBLIC|ACYCLIC|ANNOTATION|INTERFACE;
408         sym.erasure_field = type;
409         sym.members_field = WriteableScope.create(sym);
410         type.typarams_field = List.nil();
411         type.allparams_field = List.nil();
412         type.supertype_field = annotationType;
413         type.interfaces_field = List.nil();
414         return type;
415     }
416 
417     /** Constructor; enters all predefined identifiers and operators
418      *  into symbol table.
419      */
420     @SuppressWarnings("this-escape")
421     protected Symtab(Context context) throws CompletionFailure {
422         context.put(symtabKey, this);
423 
424         names = Names.instance(context);
425 
426         // Create the unknown type
427         unknownType = new UnknownType();
428 
429         messages = JavacMessages.instance(context);
430 
431         MissingInfoHandler missingInfoHandler = MissingInfoHandler.instance(context);
432 
433         Target target = Target.instance(context);
434         rootPackage = new RootPackageSymbol(names.empty, null,
435                                             missingInfoHandler,
436                                             target.runtimeUseNestAccess());
437 
438         // create the basic builtin symbols
439         unnamedModule = new ModuleSymbol(names.empty, null) {
440                 {
441                     directives = List.nil();
442                     exports = List.nil();
443                     provides = List.nil();
444                     uses = List.nil();
445                     ModuleSymbol java_base = enterModule(names.java_base);
446                     com.sun.tools.javac.code.Directive.RequiresDirective d =
447                             new com.sun.tools.javac.code.Directive.RequiresDirective(java_base,
448                                     EnumSet.of(com.sun.tools.javac.code.Directive.RequiresFlag.MANDATED));
449                     requires = List.of(d);
450                 }
451                 @Override
452                 public String toString() {
453                     return messages.getLocalizedString("compiler.misc.unnamed.module");
454                 }
455             };
456         addRootPackageFor(unnamedModule);
457         unnamedModule.enclosedPackages = unnamedModule.enclosedPackages.prepend(unnamedModule.unnamedPackage);
458 
459         errModule = new ModuleSymbol(names.empty, null) {
460                 {
461                     directives = List.nil();
462                     exports = List.nil();
463                     provides = List.nil();
464                     uses = List.nil();
465                     ModuleSymbol java_base = enterModule(names.java_base);
466                     com.sun.tools.javac.code.Directive.RequiresDirective d =
467                             new com.sun.tools.javac.code.Directive.RequiresDirective(java_base,
468                                     EnumSet.of(com.sun.tools.javac.code.Directive.RequiresFlag.MANDATED));
469                     requires = List.of(d);
470                 }
471             };
472         addRootPackageFor(errModule);
473 
474         noModule = new ModuleSymbol(names.empty, null) {
475             @Override public boolean isNoModule() {
476                 return true;
477             }
478         };
479         addRootPackageFor(noModule);
480 
481         noSymbol = new TypeSymbol(NIL, 0, names.empty, Type.noType, rootPackage) {
482             @Override @DefinedBy(Api.LANGUAGE_MODEL)
483             public <R, P> R accept(ElementVisitor<R, P> v, P p) {
484                 return v.visitUnknown(this, p);
485             }
486         };
487 
488         // create the error symbols
489         errSymbol = new ClassSymbol(PUBLIC|STATIC|ACYCLIC, names.any, null, rootPackage);
490         errType = new ErrorType(errSymbol, Type.noType);
491 
492         unknownSymbol = new ClassSymbol(PUBLIC|STATIC|ACYCLIC, names.fromString("<any?>"), null, rootPackage);
493         unknownSymbol.members_field = new Scope.ErrorScope(unknownSymbol);
494         unknownSymbol.type = unknownType;
495 
496         // initialize builtin types
497         initType(byteType, "byte", "Byte");
498         initType(shortType, "short", "Short");
499         initType(charType, "char", "Character");
500         initType(intType, "int", "Integer");
501         initType(longType, "long", "Long");
502         initType(floatType, "float", "Float");
503         initType(doubleType, "double", "Double");
504         initType(booleanType, "boolean", "Boolean");
505         initType(voidType, "void", "Void");
506         initType(botType, "<nulltype>");
507         initType(errType, errSymbol);
508         initType(unknownType, unknownSymbol);
509 
510         // the builtin class of all arrays
511         arrayClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Array, noSymbol);
512 
513         // VGJ
514         boundClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Bound, noSymbol);
515         boundClass.members_field = new Scope.ErrorScope(boundClass);
516 
517         // the builtin class of all methods
518         methodClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Method, noSymbol);
519         methodClass.members_field = new Scope.ErrorScope(boundClass);
520 
521         // Create class to hold all predefined constants and operations.
522         predefClass = new ClassSymbol(PUBLIC|ACYCLIC, names.empty, rootPackage);
523         WriteableScope scope = WriteableScope.create(predefClass);
524         predefClass.members_field = scope;
525 
526         // Get the initial completer for Symbols from the ClassFinder
527         initialCompleter = ClassFinder.instance(context).getCompleter();
528         rootPackage.members_field = WriteableScope.create(rootPackage);
529 
530         // Enter symbols for basic types.
531         scope.enter(byteType.tsym);
532         scope.enter(shortType.tsym);
533         scope.enter(charType.tsym);
534         scope.enter(intType.tsym);
535         scope.enter(longType.tsym);
536         scope.enter(floatType.tsym);
537         scope.enter(doubleType.tsym);
538         scope.enter(booleanType.tsym);
539         scope.enter(errType.tsym);
540 
541         // Enter symbol for the errSymbol
542         scope.enter(errSymbol);
543 
544         Source source = Source.instance(context);
545         if (Feature.MODULES.allowedInSource(source)) {
546             java_base = enterModule(names.java_base);
547             //avoid completing java.base during the Symtab initialization
548             java_base.completer = Completer.NULL_COMPLETER;
549             java_base.visiblePackages = Collections.emptyMap();
550         } else {
551             java_base = noModule;
552         }
553 
554         // Get the initial completer for ModuleSymbols from Modules
555         moduleCompleter = Modules.instance(context).getCompleter();
556 
557         // Enter predefined classes. All are assumed to be in the java.base module.
558         objectType = enterClass("java.lang.Object");
559         objectMethodsType = enterClass("java.lang.runtime.ObjectMethods");
560         objectsType = enterClass("java.util.Objects");
561         classType = enterClass("java.lang.Class");
562         stringType = enterClass("java.lang.String");
563         stringBufferType = enterClass("java.lang.StringBuffer");
564         stringBuilderType = enterClass("java.lang.StringBuilder");
565         cloneableType = enterClass("java.lang.Cloneable");
566         throwableType = enterClass("java.lang.Throwable");
567         serializableType = enterClass("java.io.Serializable");
568         serializedLambdaType = enterClass("java.lang.invoke.SerializedLambda");
569         varHandleType = enterClass("java.lang.invoke.VarHandle");
570         methodHandleType = enterClass("java.lang.invoke.MethodHandle");
571         methodHandlesType = enterClass("java.lang.invoke.MethodHandles");
572         methodHandleLookupType = enterClass("java.lang.invoke.MethodHandles$Lookup");
573         methodTypeType = enterClass("java.lang.invoke.MethodType");
574         errorType = enterClass("java.lang.Error");
575         illegalArgumentExceptionType = enterClass("java.lang.IllegalArgumentException");
576         interruptedExceptionType = enterClass("java.lang.InterruptedException");
577         exceptionType = enterClass("java.lang.Exception");
578         runtimeExceptionType = enterClass("java.lang.RuntimeException");
579         classNotFoundExceptionType = enterClass("java.lang.ClassNotFoundException");
580         noClassDefFoundErrorType = enterClass("java.lang.NoClassDefFoundError");
581         noSuchFieldErrorType = enterClass("java.lang.NoSuchFieldError");
582         assertionErrorType = enterClass("java.lang.AssertionError");
583         incompatibleClassChangeErrorType = enterClass("java.lang.IncompatibleClassChangeError");
584         cloneNotSupportedExceptionType = enterClass("java.lang.CloneNotSupportedException");
585         matchExceptionType = enterClass("java.lang.MatchException");
586         annotationType = enterClass("java.lang.annotation.Annotation");
587         classLoaderType = enterClass("java.lang.ClassLoader");
588         enumSym = enterClass(java_base, names.java_lang_Enum);
589         enumFinalFinalize =
590             new MethodSymbol(PROTECTED|FINAL|HYPOTHETICAL,
591                              names.finalize,
592                              new MethodType(List.nil(), voidType,
593                                             List.nil(), methodClass),
594                              enumSym);
595         listType = enterClass("java.util.List");
596         collectionsType = enterClass("java.util.Collections");
597         comparableType = enterClass("java.lang.Comparable");
598         comparatorType = enterClass("java.util.Comparator");
599         arraysType = enterClass("java.util.Arrays");
600         iterableType = enterClass("java.lang.Iterable");
601         iteratorType = enterClass("java.util.Iterator");
602         annotationTargetType = enterClass("java.lang.annotation.Target");
603         overrideType = enterClass("java.lang.Override");
604         retentionType = enterClass("java.lang.annotation.Retention");
605         deprecatedType = enterClass("java.lang.Deprecated");
606         suppressWarningsType = enterClass("java.lang.SuppressWarnings");
607         supplierType = enterClass("java.util.function.Supplier");
608         inheritedType = enterClass("java.lang.annotation.Inherited");
609         repeatableType = enterClass("java.lang.annotation.Repeatable");
610         documentedType = enterClass("java.lang.annotation.Documented");
611         elementTypeType = enterClass("java.lang.annotation.ElementType");
612         systemType = enterClass("java.lang.System");
613         autoCloseableType = enterClass("java.lang.AutoCloseable");
614         autoCloseableClose = new MethodSymbol(PUBLIC,
615                              names.close,
616                              new MethodType(List.nil(), voidType,
617                                             List.of(exceptionType), methodClass),
618                              autoCloseableType.tsym);
619         trustMeType = enterClass("java.lang.SafeVarargs");
620         nativeHeaderType = enterClass("java.lang.annotation.Native");
621         lambdaMetafactory = enterClass("java.lang.invoke.LambdaMetafactory");
622         stringConcatFactory = enterClass("java.lang.invoke.StringConcatFactory");
623         functionalInterfaceType = enterClass("java.lang.FunctionalInterface");
624         previewFeatureType = enterClass("jdk.internal.javac.PreviewFeature");
625         previewFeatureInternalType = enterSyntheticAnnotation("jdk.internal.PreviewFeature+Annotation");
626         typeDescriptorType = enterClass("java.lang.invoke.TypeDescriptor");
627         recordType = enterClass("java.lang.Record");
628         switchBootstrapsType = enterClass("java.lang.runtime.SwitchBootstraps");
629         constantBootstrapsType = enterClass("java.lang.invoke.ConstantBootstraps");
630         valueBasedType = enterClass("jdk.internal.ValueBased");
631         valueBasedInternalType = enterSyntheticAnnotation("jdk.internal.ValueBased+Annotation");
632         classDescType = enterClass("java.lang.constant.ClassDesc");
633         enumDescType = enterClass("java.lang.Enum$EnumDesc");
634         // For serialization lint checking
635         objectStreamFieldType = enterClass("java.io.ObjectStreamField");
636         objectInputStreamType = enterClass("java.io.ObjectInputStream");
637         objectOutputStreamType = enterClass("java.io.ObjectOutputStream");
638         ioExceptionType = enterClass("java.io.IOException");
639         objectStreamExceptionType = enterClass("java.io.ObjectStreamException");
640         externalizableType = enterClass("java.io.Externalizable");
641         objectInputType  = enterClass("java.io.ObjectInput");
642         objectOutputType = enterClass("java.io.ObjectOutput");
643         synthesizeEmptyInterfaceIfMissing(autoCloseableType);
644         synthesizeEmptyInterfaceIfMissing(cloneableType);
645         synthesizeEmptyInterfaceIfMissing(serializableType);
646         synthesizeEmptyInterfaceIfMissing(lambdaMetafactory);
647         synthesizeEmptyInterfaceIfMissing(serializedLambdaType);
648         synthesizeEmptyInterfaceIfMissing(stringConcatFactory);
649         synthesizeBoxTypeIfMissing(doubleType);
650         synthesizeBoxTypeIfMissing(floatType);
651         synthesizeBoxTypeIfMissing(voidType);
652 
653         // For string templates
654         stringTemplateType = enterClass("java.lang.StringTemplate");
655         templateRuntimeType = enterClass("java.lang.runtime.TemplateRuntime");
656         processorType = enterClass("java.lang.StringTemplate$Processor");
657         linkageType = enterClass("java.lang.StringTemplate$Processor$Linkage");
658 
659         // Enter a synthetic class that is used to mark internal
660         // proprietary classes in ct.sym.  This class does not have a
661         // class file.
662         proprietaryType = enterSyntheticAnnotation("sun.Proprietary+Annotation");
663 
664         // Enter a synthetic class that is used to provide profile info for
665         // classes in ct.sym.  This class does not have a class file.
666         profileType = enterSyntheticAnnotation("jdk.Profile+Annotation");
667         MethodSymbol m = new MethodSymbol(PUBLIC | ABSTRACT, names.value, intType, profileType.tsym);
668         profileType.tsym.members().enter(m);
669 
670         // Enter a class for arrays.
671         // The class implements java.lang.Cloneable and java.io.Serializable.
672         // It has a final length field and a clone method.
673         ClassType arrayClassType = (ClassType)arrayClass.type;
674         arrayClassType.supertype_field = objectType;
675         arrayClassType.interfaces_field = List.of(cloneableType, serializableType);
676         arrayClass.members_field = WriteableScope.create(arrayClass);
677         lengthVar = new VarSymbol(
678             PUBLIC | FINAL,
679             names.length,
680             intType,
681             arrayClass);
682         arrayClass.members().enter(lengthVar);
683         arrayCloneMethod = new MethodSymbol(
684             PUBLIC,
685             names.clone,
686             new MethodType(List.nil(), objectType,
687                            List.nil(), methodClass),
688             arrayClass);
689         arrayClass.members().enter(arrayCloneMethod);
690 
691         if (java_base != noModule)
692             java_base.completer = moduleCompleter::complete; //bootstrap issues
693         Options options = Options.instance(context);
694         allowPrimitiveClasses = Feature.PRIMITIVE_CLASSES.allowedInSource(source) && options.isSet("enablePrimitiveClasses");
695     }
696 
697     /** Define a new class given its name and owner.
698      */
699     public ClassSymbol defineClass(Name name, Symbol owner) {
700         ClassSymbol c = new ClassSymbol(0, name, owner);
701         c.completer = initialCompleter;
702         return c;
703     }
704 
705     /** Create a new toplevel or member class symbol with given name
706      *  and owner and enter in `classes' unless already there.
707      */
708     public ClassSymbol enterClass(ModuleSymbol msym, Name name, TypeSymbol owner) {
709         Assert.checkNonNull(msym);
710         Name flatname = TypeSymbol.formFlatName(name, owner);
711         ClassSymbol c = getClass(msym, flatname);
712         if (c == null) {
713             c = defineClass(name, owner);
714             doEnterClass(msym, c);
715         } else if ((c.name != name || c.owner != owner) && owner.kind == TYP &&
716                    c.owner.kind == PCK && ((c.flags_field & FROM_SOURCE) == 0)) {
717             // reassign fields of classes that might have been loaded with
718             // their flat names.
719             c.owner.members().remove(c);
720             c.name = name;
721             c.owner = owner;
722             c.fullname = ClassSymbol.formFullName(name, owner);
723         }
724         return c;
725     }
726 
727     public ClassSymbol getClass(ModuleSymbol msym, Name flatName) {
728         Assert.checkNonNull(msym, flatName::toString);
729         return classes.getOrDefault(flatName, Collections.emptyMap()).get(msym);
730     }
731 
732     public PackageSymbol lookupPackage(ModuleSymbol msym, Name flatName) {
733         return lookupPackage(msym, flatName, false);
734     }
735 
736     private PackageSymbol lookupPackage(ModuleSymbol msym, Name flatName, boolean onlyExisting) {
737         Assert.checkNonNull(msym);
738 
739         if (flatName.isEmpty()) {
740             //unnamed packages only from the current module - visiblePackages contains *root* package, not unnamed package!
741             return msym.unnamedPackage;
742         }
743 
744         if (msym == noModule) {
745             return enterPackage(msym, flatName);
746         }
747 
748         msym.complete();
749 
750         PackageSymbol pack;
751 
752         pack = msym.visiblePackages.get(flatName);
753 
754         if (pack != null)
755             return pack;
756 
757         pack = getPackage(msym, flatName);
758 
759         if ((pack != null && pack.exists()) || onlyExisting)
760             return pack;
761 
762         boolean dependsOnUnnamed = msym.requires != null &&
763                                    msym.requires.stream()
764                                                 .map(rd -> rd.module)
765                                                 .anyMatch(mod -> mod == unnamedModule);
766 
767         if (dependsOnUnnamed) {
768             //msyms depends on the unnamed module, for which we generally don't know
769             //the list of packages it "exports" ahead of time. So try to lookup the package in the
770             //current module, and in the unnamed module and see if it exists in one of them
771             PackageSymbol unnamedPack = getPackage(unnamedModule, flatName);
772 
773             if (unnamedPack != null && unnamedPack.exists()) {
774                 msym.visiblePackages.put(unnamedPack.fullname, unnamedPack);
775                 return unnamedPack;
776             }
777 
778             pack = enterPackage(msym, flatName);
779             pack.complete();
780             if (pack.exists())
781                 return pack;
782 
783             unnamedPack = enterPackage(unnamedModule, flatName);
784             unnamedPack.complete();
785             if (unnamedPack.exists()) {
786                 msym.visiblePackages.put(unnamedPack.fullname, unnamedPack);
787                 return unnamedPack;
788             }
789 
790             return pack;
791         }
792 
793         return enterPackage(msym, flatName);
794     }
795 
796     private static final Map<ModuleSymbol, ClassSymbol> EMPTY = new HashMap<>();
797 
798     public void removeClass(ModuleSymbol msym, Name flatName) {
799         classes.getOrDefault(flatName, EMPTY).remove(msym);
800     }
801 
802     public Iterable<ClassSymbol> getAllClasses() {
803         return () -> Iterators.createCompoundIterator(classes.values(), v -> v.values().iterator());
804     }
805 
806     private void doEnterClass(ModuleSymbol msym, ClassSymbol cs) {
807         classes.computeIfAbsent(cs.flatname, n -> new HashMap<>()).put(msym, cs);
808     }
809 
810     /** Create a new member or toplevel class symbol with given flat name
811      *  and enter in `classes' unless already there.
812      */
813     public ClassSymbol enterClass(ModuleSymbol msym, Name flatname) {
814         Assert.checkNonNull(msym);
815         PackageSymbol ps = lookupPackage(msym, Convert.packagePart(flatname));
816         Assert.checkNonNull(ps);
817         Assert.checkNonNull(ps.modle);
818         ClassSymbol c = getClass(ps.modle, flatname);
819         if (c == null) {
820             c = defineClass(Convert.shortName(flatname), ps);
821             doEnterClass(ps.modle, c);
822             return c;
823         } else
824             return c;
825     }
826 
827     /** Check to see if a package exists, given its fully qualified name.
828      */
829     public boolean packageExists(ModuleSymbol msym, Name fullname) {
830         Assert.checkNonNull(msym);
831         PackageSymbol pack = lookupPackage(msym, fullname, true);
832         return pack != null && pack.exists();
833     }
834 
835     /** Make a package, given its fully qualified name.
836      */
837     public PackageSymbol enterPackage(ModuleSymbol currModule, Name fullname) {
838         Assert.checkNonNull(currModule);
839         PackageSymbol p = getPackage(currModule, fullname);
840         if (p == null) {
841             Assert.check(!fullname.isEmpty(), () -> "rootPackage missing!; currModule: " + currModule);
842             p = new PackageSymbol(
843                     Convert.shortName(fullname),
844                     enterPackage(currModule, Convert.packagePart(fullname)));
845             p.completer = initialCompleter;
846             p.modle = currModule;
847             doEnterPackage(currModule, p);
848         }
849         return p;
850     }
851 
852     private void doEnterPackage(ModuleSymbol msym, PackageSymbol pack) {
853         packages.computeIfAbsent(pack.fullname, n -> new HashMap<>()).put(msym, pack);
854         msym.enclosedPackages = msym.enclosedPackages.prepend(pack);
855     }
856 
857     private void addRootPackageFor(ModuleSymbol module) {
858         doEnterPackage(module, rootPackage);
859         PackageSymbol unnamedPackage = new PackageSymbol(names.empty, rootPackage) {
860                 @Override
861                 public String toString() {
862                     return messages.getLocalizedString("compiler.misc.unnamed.package");
863                 }
864             };
865         unnamedPackage.modle = module;
866         //we cannot use a method reference below, as initialCompleter might be null now
867         unnamedPackage.completer = s -> initialCompleter.complete(s);
868         unnamedPackage.flags_field |= EXISTS;
869         module.unnamedPackage = unnamedPackage;
870     }
871 
872     public PackageSymbol getPackage(ModuleSymbol module, Name fullname) {
873         return packages.getOrDefault(fullname, Collections.emptyMap()).get(module);
874     }
875 
876     public ModuleSymbol enterModule(Name name) {
877         ModuleSymbol msym = modules.get(name);
878         if (msym == null) {
879             msym = ModuleSymbol.create(name, names.module_info);
880             addRootPackageFor(msym);
881             msym.completer = s -> moduleCompleter.complete(s); //bootstrap issues
882             modules.put(name, msym);
883         }
884         return msym;
885     }
886 
887     public ModuleSymbol getModule(Name name) {
888         return modules.get(name);
889     }
890 
891     //temporary:
892     public ModuleSymbol inferModule(Name packageName) {
893         if (packageName.isEmpty())
894             return java_base == noModule ? noModule : unnamedModule;//!
895 
896         ModuleSymbol msym = null;
897         Map<ModuleSymbol,PackageSymbol> map = packages.get(packageName);
898         if (map == null)
899             return null;
900         for (Map.Entry<ModuleSymbol,PackageSymbol> e: map.entrySet()) {
901             if (!e.getValue().members().isEmpty()) {
902                 if (msym == null) {
903                     msym = e.getKey();
904                 } else {
905                     return null;
906                 }
907             }
908         }
909         return msym;
910     }
911 
912     public List<ModuleSymbol> listPackageModules(Name packageName) {
913         if (packageName.isEmpty())
914             return List.nil();
915 
916         List<ModuleSymbol> result = List.nil();
917         Map<ModuleSymbol,PackageSymbol> map = packages.get(packageName);
918         if (map != null) {
919             for (Map.Entry<ModuleSymbol, PackageSymbol> e: map.entrySet()) {
920                 if (!e.getValue().members().isEmpty()) {
921                     result = result.prepend(e.getKey());
922                 }
923             }
924         }
925         return result;
926     }
927 
928     public Collection<ModuleSymbol> getAllModules() {
929         return modules.values();
930     }
931 
932     public Iterable<ClassSymbol> getClassesForName(Name candidate) {
933         return classes.getOrDefault(candidate, Collections.emptyMap()).values();
934     }
935 
936     public Iterable<PackageSymbol> getPackagesForName(Name candidate) {
937         return packages.getOrDefault(candidate, Collections.emptyMap()).values();
938     }
939 }